back to article Behind time and way over budget, but the James Webb Space Telescope has finally been put together

The long-awaited James Webb Space Telescope has finally been assembled, NASA announced on Wednesday. The project has had a rocky road. Originally scheduled to enter space as early as 2007, the instrument has been bedeviled with numerous delays, including a redesign and an accidentally ripped sunshield that had to be repaired. …

  1. Yet Another Anonymous coward Silver badge

    Main mirror

    Just to be clear, the 12 segments are just an image of the partially assembled 16 segment mirror - the design hasn't changed

    1. Joe Gurman

      Re: Main mirror

      Exactly. The two uttermost panels of mirror are folded back 90 degrees. See: https://www.nasa.gov/feature/goddard/2019/nasa-s-james-webb-space-telescope-has-been-assembled-for-the-first-time for a another view.

      1. Yet Another Anonymous coward Silver badge

        Re: Main mirror

        25 years ago there was a design with a single 6.5m monolithic mirror.

        It needed an Ariane5 with a special 'power bulge' nose cone.

        But it was imperative that the launch be on an American rocket, hence the complex folding design. Then the cost got so high they needed european partners.....

        1. lglethal Silver badge
          Trollface

          Re: Main mirror

          Politics getting in the way of scientific endeavour and pushing costs into overdrive? Say it aint so...

          1. Chris G Silver badge

            Re: Main mirror

            Politics getting in the way?

            Shirley that would never happen, politicians respect pure science.

            Don't they?

            1. Yet Another Anonymous coward Silver badge

              Re: Main mirror

              It was more the old old story of :

              To avoid X we have to do this complicated thing Y

              Complicated thing Y took too long, cost too much

              Now we need to bring X in

              But we are still using Y with X

              That pretty much writes every el'reg story about government IT projects

            2. Yet Another Anonymous coward Silver badge

              Re: Main mirror

              >Politics getting in the way?

              Ah the stories I could tell of Hubble.

              When it was first launched the mirror problem gave the public impression was that it was totally fscked.

              In fact it was just 10x better than anything on the ground, but not 100x better

              So there was a plan to take some impressive pretty pictures of pretty objects to show the public.

              These were taken by a European camera and so had the ESA logo as well as the NASA logo. But the ESA logo is square, so at the same width looked larger than the NASA logo. So the publication was blocked until an agreement could be reached about the relative areas of the two logos.....

  2. Scott Broukell
    Coat

    "Oh! what a tangled Webb we weave" - everybody in the project assembly team (probably). Mine's the one with the poems of Walter Scott in the pocket.

  3. Anonymous South African Coward Silver badge

    Who's gonna launch this new toy?

    1. Pete4000uk

      Ariane 5

      1. adam 40 Bronze badge

        Well, let's hope it doesn't blow up on the pad...

  4. STOP_FORTH
    Boffin

    Segmented mirrors

    I was at Bologna yesterday and did the astronomy tour at the university. Guido Horn-d'Arturo made a large segmented mirror with 61 hexagons after WWII. Only pointed upward though, they had to move the photographic plates to compensate for Earth's movement.

    Top boffinry!

    1. Yet Another Anonymous coward Silver badge

      Re: Segmented mirrors

      They were probably spherical mirrors (like an individual small telescope mirror) these are each different parabolic shapes as if you had made one vast parabolic mirror and sliced it up. It is WAY harder to build even with modern CNC machines

      It was first done in the early 90s at Keck but took years and a few technology breakthroughs to eventually figure the mirror correctly. And learning how to align it perfectly took more years.

      So doing this in space and having it faultlessly unfold and align perfectly a million miles away is going to be sphincter clenching (assuming they ever finish building it)

      1. Anonymous Coward
        Anonymous Coward

        Re: Segmented mirrors

        "(assuming they ever finish building it)"

        ... so now we are at knee-jerk comments without reading the frigging HEADLINE ?

        1. quxinot Silver badge

          Re: Segmented mirrors

          >... so now we are at knee-jerk comments without reading the frigging HEADLINE ?

          "Now"?

      2. STOP_FORTH

        Re: Segmented mirrors

        Well, they looked like hexagons to me. Couldn't tell if they were flat or subtly curved. Alignment was done manually with three screws per mirror. Way before Keck. This was the first one.

        1. Yet Another Anonymous coward Silver badge

          Re: Segmented mirrors

          Hexagons but cut out of small identical normal mirrors. Each focusses it's light at the same position so you get the light gathering of a big mirror but not the image quality.

          To make Keck each element is a different off-axis parabola, incrediblly difficult to make

          1. STOP_FORTH
            Happy

            Re: Segmented mirrors

            They were only using it as a zenith telescope to determine position of stars, so image quality wasn't a priority. Apparently they were spherically ground mirrors, though that is difficult to see with eyeballs!

            His assistant (who was the guy adjusting all the screws) subsequently went to the US and is popularly credited with inventing segmented mirrors. Although he did improve them enormously I think the original guy should get some credit.

            Why do the Septics claim to have invented everything? They are nearly as bad as the Sweaty Socks.

  5. Bonzo_red

    Will UK astronomers be given a proportion of the access allocated to ESA?

    1. Throatwarbler Mangrove Silver badge
      Holmes

      If the UK pays its Brexit "divorce bill." So . . . no.

      1. Yet Another Anonymous coward Silver badge

        Esa is nothing to do with the EU so yes.

        Generally though instruments are built by, and the time allocated to, institutions who invented and paid. Esa is normally just a contractor

  6. sitta_europea Bronze badge

    Well, all that's left to do now is sit the fucking thing on top of five hundred tons of explosives, and set light to it...

    1. ibmalone Silver badge

      It's how all the best parties start.

  7. Any other name

    Space telescopes, R&D, and delays

    Originally scheduled to enter space as early as 2007, the instrument has been bedeviled with numerous delays ...

    Delays and cost overruns are par for the course whenever you do something at the utmost limit of the technically possible, and especially so if you do this for the first time ever.

    I have a very nice book by Robert W. Smith on my book shelf, with the title "The Space Telescope: A study of NASA, science, technology, and politics". It was published in 1989 - a year before Hubble was launched, and four year before it first worked as intended.

    The author was contracted by NASA and NSF to document the construction and the initial operation of the space telescope; however by 1986 - after hundreds of those involved were interviewed, the scientific, technical, and legislative processes were extensively documented, the manuscript was completed, and the contracts have run out - the launch was still nowhere in sight and it remained uncertain whether it would ever happen at all.

    Luckily, it did happen, and the rest is history - including the book, which I highly recommend to anyone interested in space science and science politics.

    1. Anonymous Coward
      Anonymous Coward

      Re: Space telescopes, R&D, and delays

      Another good read is about the Spitzer telescope: Rieke, "The Last of the Great Observatories" (NASA's AO released 1983, launched 2003. Written by an astrophysicist but his comments on PM are very interesting.)

  8. 0laf Silver badge
    Alien

    I for one....

    I for one... sincerely hope the whole kit and kaboodle comes together on time and works faultlessly.

    I wanna see the science from this big gold bastard

    1. hoola Bronze badge

      Re: I for one....

      It will be great if it does get up to L2 and deploys all the various bits so it works. The whole thing is just so complicated basic odds suggest that something will not quite function as expected.

      I believe the mirror is also dynamic as well and each panel needs to be manipulated to maintain the overall precision the instruments need.

      There is just so much to go wrong and so very little that can done once it is at L2.

      Finger crossed....

      1. dobbin99

        Re: I for one....

        Its alright Elon will have Starship working by then and will be able to send out a Tesla Repair Centre truck :)

  9. 89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921 Bronze badge

    It will see much deeper into Uranus

  10. Carpet Deal 'em Bronze badge
    Joke

    Let's hope the sunshield doesn't get ripped off again, eh?

    But that Nigerian prince was so friendly!

  11. 89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921 Bronze badge

    Taking Uranus's temperature will be less fun

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